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The first V8 to enter the well-known family that started with the legendary four cylinder E30 of 20 years ago is astonishingly lighter than the 3.2-litre six cylinder M3 engine.
At 202kg, the meat of the M3 — cast in the same foundry that gives birth to BMW's Formula One engines — is 15kg lighter than the straight-six motor. It screams to a maximum engine speed of 8300rpm, cracking 309kW and generating 400Nm of torque.
These figures were predicted before the official announcement late last week but the big news is the lower weight of the shorter V8 powerplant that can be placed further behind the front axle.
Significantly, the maximum torque figure arrives below 4000rpm, giving it far greater low-down twist than the V10 M5 engine from which it is based. In fact, the torque spread is extremely flexible, with 85 per cent of peak pulling power maintained above 6500rpm.
BMW does not like reference to the fact it is simply a V10 with two cylinders chopped off.
That, it says, does not do the powerplant justice as, unlike the V10, the V8 has milder torque pressures so there is no need for high-pressure oil set-ups for the double VANOS continuously variable intake and exhaust cam adjustment.
The world's most anticipated car of 2007 will be shown at the Frankfurt motor show in September and available later in the year.
This super coupe promises fuel savings over the six cylinder of up to 8 per cent.
It is fractionally behind the current M3 in the power-to-litres ratio, with the V8 measuring 77.2kW/litre compared with the six cylinders 77.6kW/litre. But BMW has left plenty of room to develop the V8.
For example, it doesn't get the high-precision direct-injection technology afforded many of its new-generation engines. It also uses a conventional water pump rather than an electric pump so there are plenty of areas where BMW can raise the power bar for the four-litre unit in future. Perhaps the yardstick by which any bullet-like production car is measured remains the lap time it can generate at Germany's fabled Nordschliefe circuit. BMW engineers were cagey when cornered about suggestions the V8 is up to 15 seconds a lap quicker than the six cylinder. Official timed runs are slated for June, however it is known that what the M3 has produced on the track so far is impressive — although it is not as quick as an M5, nor for that matter the superlight M3 CSL, which has the bragging rights as the fastest M car.
Curiously, there was no concept version of the M3 shown when BMW had the official press reveal of the engine details at M headquarters in Munich last week.
When the concept car was shown at the Geneva show in early March there was a considerable backlash over the huge power dome on the bonnet.
Blogs gave the bonnet bulge a universal thumbs down, forcing BMW to possibly fine-tune some of the design elements.
The new V8 engine test facility that is encased in 2800m2 of reinforced concrete tests extreme temperature fluctuations from -20C to plus 60C.
Durability runs, which mirror the F1 process BMW undertakes with its Sauber program, have been conducted over nine-day periods at an average speed of 183km/h, which in real-world tests BMW calculates would take between six to eight weeks.
The Engine Control Unit, developed by Siemens, is based on the M5 and uses three processors. Up to 200 million calculations are made per second and each cylinder is scanned 250 times per second. This MSS60 management system is highly sophisticated and co-ordinates all of the engine functions with the various other control units on the car.
The M3s knockout lightweight V8 is down on torque compared to Audi's fabulous RS4 rocketship and is expected also to be overshadowed by Mercedes-Benz's much anticipated and forthcoming C63 AMG.
First drives of the M3 will be slated for July, when the wild child V8 coupe is put through its paces at the Ascari racetrack in Spain.
